A hot stage for a manufacturing process is shown in the accompanying figure, where a slab of

Question:

A €œhot stage€ for a manufacturing process is shown in the accompanying figure, where a slab of stainless steel is mounted on top of an electrical resistance heater. The stainless steel slab is 20 cm wide, 60 cm long, and 2 cm thick. A load material, which is placed on top of the stainless steel hot plate, requires a power input of 600 W. The dimensions of the load material are 20 cm in width, 60 cm in length (in the direction of air flow), and 0.5 cm thick. The surface temperature of the load material exposed to the air is measured to be T_s= 207°C (480 K). The air flow has a bulk velocity of 3 m/s, and the ambient temperature of the air is maintained at 47°C (320 K). The thermal conductivity of stainless steel (hot stage) is k_s= 16 W/m · K, and the thermal conductivity of the load material is k_m= 2 W/m · K.
a. Estimate the heat loss from the surface of load material, in Watts.
b. What is the total power output, in Watts, required for the heater, assuming there are no heat-transfer losses from the sides of the plate?
c. What is the temperature at the interface between the stainless steel hot stage and the load material?
d. What is the estimated temperature at the base of the hot stage in contact with the electrical resistance heater (T₂)?

V = 3.0 m/sec bulk air flow V. = 47 °C 9 Joss L= 0.6 m -Tg = 207 °C -T, = ? load material (needs 600 W net power) %3D